Heavy metal accumulation in selected fish species from Pulicat Lake, India, and health risk assessment

Heavy metal pollution in aquatic systems has become a major problem worldwide. The present study was designed to assess bioaccumulation of metals, Cu, Zn, Pb, and Cr, in fish species such as Lutjanus fulviflamma, Chanos chanos, Arius sp., and Terapon jarbua, commonly present in the Pulicat Lake, a brackish water ecosystem located in north Chennai coastal region, southeast India. Mean concentration of Cu and Cr in the sediment samples were 123.1μg/g and 90.1μg/g, respectively. The order of metal prevalence in water and sediment samples were Pb>Cr>Zn>Cu and Cu>Cr>Pb>Zn, respectively. However, in fish samples, the order of metal accumulation was Cu>Cr>Zn>Pb. Mean concentration of Cu in L. fulviflamma, C. chanos, Arius sp., and T. jarbua was 10.5μg/g, 25.5μg/g, 19.0μg/g, and 23.6μg/g, respectively. Mean Cr concentration in the animals varied from 1.19μg/g to 23.1μg/g with highest accumulation in the liver of Arius sp. In general, maximum accumulation of metals is mostly observed in the gills of the organisms. Although the concentration of Cu and Cr in the muscles was above World Health Organization's permissible limit, the Estimated Daily Intake values were below the standard reference dose which means that the muscle tissues of the fishes are safe for human consumption.